1. Technical Field
The present invention relates generally to an improved data processing system, and in particular, to a method and apparatus for generating a data stream. Still more particularly, the present invention relates to a method and apparatus for generating or rendering a metadata stream.
2. Description of Related Art
Currently, metadata streams are created in the order that applications call graphical functions. Metadata is data about data. For example, the title, subject, author, and size of a file constitute metadata about a file. With respect to graphics, the current position, color, and size of a primitive, such as a box, constitute metadata for the box. With respect to a primitive, in computer graphics, a shape, such as a line, circle, curve, or polygon, that can be drawn, stored, and manipulated as a discrete entity by a graphics program. A primitive is one of the elements from which a large graphic design is created.
Metadata streams may be sent to printers and other output mediums for output, and/or stored for later processing, information transfer to other systems or applications. With respect to a printer, a printer is a computer peripheral that outputs text and/or a computer generated image on paper or on another medium. The amount of data sent to a printer can vary depending on information to be printed in a print job. A job is a specified amount of processing performed by a unit such as a computer or printer. Many printers do not have sufficient memory to print a full sheet. As a result, some printers are capable of printing only parts of a page at a time as a result of these memory constraints. This kind of printing is also referred to as "banding". For each band, a printer has to replay the entire metadata stream clipping the output to the current band. This reduces the performance in the output of such a printer. For example, if a printer has sufficient memory only for one quarter of a page, four passes of the metadata are required. In each pass, the portion or quarter of the metadata stream is used to print the portion or "band" of the page. As a result, in this example, four passes through the metadata would be required for one page of output.
Therefore, this is one example of how it would be desirable to have an improved method and apparatus for creating a metadata stream that can be processed more efficiently.